1. Field of the Invention
The present invention relates to an information processing apparatus for an electronic filing apparatus for, for example, recording image information and retrieving it and, in particular, to an information processing apparatus of such a type that, between a system including a main board and a corresponding expansion board mounted in a corresponding expansion slot, the apparatus makes a given interruption to the expansion board, via a system bus, on each slot basis.
2. Description of the Related Art
In a conventional electronic filing apparatus for recording image information and retrieving it, a plurality of expansion slots equipped with a corresponding expansion board are connected, via a system bus, to a main board of a function expansion system.
If in this case, a common interruption line is connected to the expansion slots and, with the upper bits of an I/O address varied from slot to slot, a corresponding expansion is selected with a corresponding decoder signal, then an interruption can be implemented, eve if the individual expansion board is provided in the corresponding expansion slot, so that a function expansion can be achieved.
Since, however, the number of a common interruption signal lines in the system bus which are provided common to the respective expansion slots is initially given, the number of the expansion slots is increased and, if an interruption is to be independently made to a corresponding expansion slot, then a shortage in the number of interruption signal lines is encountered in a design layout.